**4.2 Inoculum**

The reactor was inoculated with methanogenically active biomass from a laboratory-scale anaerobic reactor processing olive mill wastewater. The composition and features of the biomass used were: pH, 7.2; total solids (TS), 60.3 g/L; mineral solids (MS), 19.3 g/L; volatile solids (VS), 41.0 g/L; total suspended solids (TSS), 59.9 g/L; mineral suspended solids (MSS), 18.8 g/L; volatile suspended solids (VSS), 41.1 g/L.
